1 files changed, 288 insertions, 0 deletions
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
new file mode 100644
index 0000000..3aeedd2
--- /dev/null
+++ b/arch/arm/vfp/vfpmodule.c
@@ -0,0 +1,288 @@
+/*
+ *  linux/arch/arm/vfp/vfpmodule.c
+ *
+ *  Copyright (C) 2004 ARM Limited.
+ *  Written by Deep Blue Solutions Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <asm/vfp.h>
+
+#include "vfpinstr.h"
+#include "vfp.h"
+
+/*
+ * Our undef handlers (in entry.S)
+ */
+void vfp_testing_entry(void);
+void vfp_support_entry(void);
+
+void (*vfp_vector)(void) = vfp_testing_entry;
+union vfp_state *last_VFP_context;
+
+/*
+ * Dual-use variable.
+ * Used in startup: set to non-zero if VFP checks fail
+ * After startup, holds VFP architecture
+ */
+unsigned int VFP_arch;
+
+/*
+ * Per-thread VFP initialisation.
+ */
+void vfp_flush_thread(union vfp_state *vfp)
+{
+	memset(vfp, 0, sizeof(union vfp_state));
+
+	vfp->hard.fpexc = FPEXC_ENABLE;
+	vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
+
+	/*
+	 * Disable VFP to ensure we initialise it first.
+	 */
+	fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_ENABLE);
+
+	/*
+	 * Ensure we don't try to overwrite our newly initialised
+	 * state information on the first fault.
+	 */
+	if (last_VFP_context == vfp)
+		last_VFP_context = NULL;
+}
+
+/*
+ * Per-thread VFP cleanup.
+ */
+void vfp_release_thread(union vfp_state *vfp)
+{
+	if (last_VFP_context == vfp)
+		last_VFP_context = NULL;
+}
+
+/*
+ * Raise a SIGFPE for the current process.
+ * sicode describes the signal being raised.
+ */
+void vfp_raise_sigfpe(unsigned int sicode, struct pt_regs *regs)
+{
+	siginfo_t info;
+
+	memset(&info, 0, sizeof(info));
+
+	info.si_signo = SIGFPE;
+	info.si_code = sicode;
+	info.si_addr = (void *)(instruction_pointer(regs) - 4);
+
+	/*
+	 * This is the same as NWFPE, because it's not clear what
+	 * this is used for
+	 */
+	current->thread.error_code = 0;
+	current->thread.trap_no = 6;
+
+	force_sig_info(SIGFPE, &info, current);
+}
+
+static void vfp_panic(char *reason)
+{
+	int i;
+
+	printk(KERN_ERR "VFP: Error: %s\n", reason);
+	printk(KERN_ERR "VFP: EXC 0x%08x SCR 0x%08x INST 0x%08x\n",
+		fmrx(FPEXC), fmrx(FPSCR), fmrx(FPINST));
+	for (i = 0; i < 32; i += 2)
+		printk(KERN_ERR "VFP: s%2u: 0x%08x s%2u: 0x%08x\n",
+		       i, vfp_get_float(i), i+1, vfp_get_float(i+1));
+}
+
+/*
+ * Process bitmask of exception conditions.
+ */
+static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_regs *regs)
+{
+	int si_code = 0;
+
+	pr_debug("VFP: raising exceptions %08x\n", exceptions);
+
+	if (exceptions == (u32)-1) {
+		vfp_panic("unhandled bounce");
+		vfp_raise_sigfpe(0, regs);
+		return;
+	}
+
+	/*
+	 * If any of the status flags are set, update the FPSCR.
+	 * Comparison instructions always return at least one of
+	 * these flags set.
+	 */
+	if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V))
+		fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V);
+
+	fpscr |= exceptions;
+
+	fmxr(FPSCR, fpscr);
+
+#define RAISE(stat,en,sig)				\
+	if (exceptions & stat && fpscr & en)		\
+		si_code = sig;
+
+	/*
+	 * These are arranged in priority order, least to highest.
+	 */
+	RAISE(FPSCR_IXC, FPSCR_IXE, FPE_FLTRES);
+	RAISE(FPSCR_UFC, FPSCR_UFE, FPE_FLTUND);
+	RAISE(FPSCR_OFC, FPSCR_OFE, FPE_FLTOVF);
+	RAISE(FPSCR_IOC, FPSCR_IOE, FPE_FLTINV);
+
+	if (si_code)
+		vfp_raise_sigfpe(si_code, regs);
+}
+
+/*
+ * Emulate a VFP instruction.
+ */
+static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs)
+{
+	u32 exceptions = (u32)-1;
+
+	pr_debug("VFP: emulate: INST=0x%08x SCR=0x%08x\n", inst, fpscr);
+
+	if (INST_CPRTDO(inst)) {
+		if (!INST_CPRT(inst)) {
+			/*
+			 * CPDO
+			 */
+			if (vfp_single(inst)) {
+				exceptions = vfp_single_cpdo(inst, fpscr);
+			} else {
+				exceptions = vfp_double_cpdo(inst, fpscr);
+			}
+		} else {
+			/*
+			 * A CPRT instruction can not appear in FPINST2, nor
+			 * can it cause an exception.  Therefore, we do not
+			 * have to emulate it.
+			 */
+		}
+	} else {
+		/*
+		 * A CPDT instruction can not appear in FPINST2, nor can
+		 * it cause an exception.  Therefore, we do not have to
+		 * emulate it.
+		 */
+	}
+	return exceptions;
+}
+
+/*
+ * Package up a bounce condition.
+ */
+void VFP9_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
+{
+	u32 fpscr, orig_fpscr, exceptions, inst;
+
+	pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc);
+
+	/*
+	 * Enable access to the VFP so we can handle the bounce.
+	 */
+	fmxr(FPEXC, fpexc & ~(FPEXC_EXCEPTION|FPEXC_INV|FPEXC_UFC|FPEXC_IOC));
+
+	orig_fpscr = fpscr = fmrx(FPSCR);
+
+	/*
+	 * If we are running with inexact exceptions enabled, we need to
+	 * emulate the trigger instruction.  Note that as we're emulating
+	 * the trigger instruction, we need to increment PC.
+	 */
+	if (fpscr & FPSCR_IXE) {
+		regs->ARM_pc += 4;
+		goto emulate;
+	}
+
+	barrier();
+
+	/*
+	 * Modify fpscr to indicate the number of iterations remaining
+	 */
+	if (fpexc & FPEXC_EXCEPTION) {
+		u32 len;
+
+		len = fpexc + (1 << FPEXC_LENGTH_BIT);
+
+		fpscr &= ~FPSCR_LENGTH_MASK;
+		fpscr |= (len & FPEXC_LENGTH_MASK) << (FPSCR_LENGTH_BIT - FPEXC_LENGTH_BIT);
+	}
+
+	/*
+	 * Handle the first FP instruction.  We used to take note of the
+	 * FPEXC bounce reason, but this appears to be unreliable.
+	 * Emulate the bounced instruction instead.
+	 */
+	inst = fmrx(FPINST);
+	exceptions = vfp_emulate_instruction(inst, fpscr, regs);
+	if (exceptions)
+		vfp_raise_exceptions(exceptions, inst, orig_fpscr, regs);
+
+	/*
+	 * If there isn't a second FP instruction, exit now.
+	 */
+	if (!(fpexc & FPEXC_FPV2))
+		return;
+
+	/*
+	 * The barrier() here prevents fpinst2 being read
+	 * before the condition above.
+	 */
+	barrier();
+	trigger = fmrx(FPINST2);
+	fpscr = fmrx(FPSCR);
+
+ emulate:
+	exceptions = vfp_emulate_instruction(trigger, fpscr, regs);
+	if (exceptions)
+		vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
+}
+ 
+/*
+ * VFP support code initialisation.
+ */
+static int __init vfp_init(void)
+{
+	unsigned int vfpsid;
+
+	/*
+	 * First check that there is a VFP that we can use.
+	 * The handler is already setup to just log calls, so
+	 * we just need to read the VFPSID register.
+	 */
+	vfpsid = fmrx(FPSID);
+
+	printk(KERN_INFO "VFP support v0.3: ");
+	if (VFP_arch) {
+		printk("not present\n");
+	} else if (vfpsid & FPSID_NODOUBLE) {
+		printk("no double precision support\n");
+	} else {
+		VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT;  /* Extract the architecture version */
+		printk("implementor %02x architecture %d part %02x variant %x rev %x\n",
+			(vfpsid & FPSID_IMPLEMENTER_MASK) >> FPSID_IMPLEMENTER_BIT,
+			(vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT,
+			(vfpsid & FPSID_PART_MASK) >> FPSID_PART_BIT,
+			(vfpsid & FPSID_VARIANT_MASK) >> FPSID_VARIANT_BIT,
+			(vfpsid & FPSID_REV_MASK) >> FPSID_REV_BIT);
+		vfp_vector = vfp_support_entry;
+	}
+	return 0;
+}
+
+late_initcall(vfp_init);